﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Input;
using System.Diagnostics;

namespace FrontEnd {
   public class RelayCommand : ICommand {
        #region fields

        readonly Action<object> _execute;
        readonly Predicate<object> _canExecute;

        #endregion fields

        #region constructors

        public RelayCommand(Action<object> execute) 
            : this(execute, null)
        {
        }

        public RelayCommand(Action<object> execute, Predicate<object> canExecute) {

            if (execute == null)
                throw new ArgumentNullException("execute");
            _execute = execute;
            _canExecute = canExecute;
        }

        #endregion fields


        #region ICommand members
       // [DebuggerStepThrough]
        public bool CanExecute(object parameter) {
            return _canExecute == null || _canExecute(parameter);
        }

        public event EventHandler CanExecuteChanged {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }
        public void Execute(object parameter) {
            _execute(parameter);
        }

        #endregion 

    }
}
